FRESNO, Calif. (AP) -- A tiny pest capable of carrying and spreading a disease deadly to citrus trees has been found in the heart of California's citrus belt, agriculture officials said Monday.

An Asian citrus psyllid was discovered in a commercial citrus orchard near Strathmore, southeast of Visalia, Tulare County Agricultural Commissioner Marilyn Kinoshita said.

The insect was identified Friday on a trap pulled from a tree by workers for the California Department of Food and Agriculture, she said.

The psyllid was not in suitable condition to be tested for the bacteria that causes the disease, California Department of Food and Agriculture spokesman Steve Lyle said.

Trees in the area did not show any signs of the disease, and the department intends to deploy additional traps and survey other nearby citrus trees, he said.

It's only the second psyllid found in the San Joaquin Valley. The first was discovered in February in Tulare County, about four miles away. It also was not suitable for testing.

Many other psyllids have been found in Southern California.

Thus far, none of the psyllids have tested positive for the deadly bacteria known by its Chinese name Huanglongbing and also called citrus greening.

The state considers testing every psyllid found in a trap but many are too dry -- so the state does not know if those psyllids carried Huanglongbing, Lyle said.

The disease has decimated the citrus sector in Florida and other parts of the world, but it hasn't touched California's $1.8 billion industry.

"It's a cause for alarm, but we can't overreact just yet," said Joel Nelson, president of California Citrus Mutual, a nonprofit group representing citrus farmers. "We hope it's an isolated find, a hitchhiker. We're sitting and holding our breaths."

There are no known pesticides or other methods to combat the disease. It can only be eliminated by finding and eliminating the insect carrier.

California growers have taxed themselves to fund a psyllid trapping program that aims to eliminate the bacteria carrier before it can spread the disease, Nelson said.

Huanglongbing is hard to detect visually because the bacteria can be present in a tree for a year or longer before symptoms can be spotted. Once infected, a tree dies within five years. Typically, a healthy citrus tree can be productive for decades.

The psyllid was first detected in Southern California in 2008 and is known to exist in the region mostly in ornamental or backyard trees.

Since then, the state has recorded nearly 43,000 reports of psyllid detection -- some with multiple insects -- in Southern California, all without the bacteria, Lyle said.

One tree infected with the disease was discovered in the Hacienda Heights area of Los Angeles County -- but scientists found no infected psyllids.

Tulare County has 119,000 acres of citrus, 61 citrus packing sheds and four juice plants.